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城市建设用地的潜在生态适宜性评价——以上海市宝山区为例 总被引：1，自引：0，他引：1
在城市快速扩张的区域,传统基于土地利用现状的生态适宜性评价方法在支持未来城市建设用地的开发决策方面具有一定的局限性。本文首次提出了城市建设用地潜在生态适宜性评价的概念和方法,把模拟预测得到的未来城市土地利用分布作为重要因子加入生态适宜性评价框架,生成更适合于未来城市建设用地规划决策的潜在生态适宜性评价结果。以上海市宝山区为例,空间化展现城市用地扩张背景下的2050年城市建设用地潜在生态适宜性分布情况,并与传统生态适宜性评价结果进行空间量化对比分析。分析结果表明,潜在生态适宜性评价有效降低了不适宜及较不适宜开发用地与未来城市建成区重叠度较高的矛盾（分别由9.74%和22.7%降低为0.0%和14.5%）,能更好地匹配城市开发边界规划和生态空间规划,突显未来发展过程中的生态保护重点区域。本文实证了新方法的科学性和有效性,该方法能更好地为城市扩张背景下的生态城市规划提供决策支持。 相似文献
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珠江三角洲建设用地开发利用极限研究 总被引：1，自引：1，他引：0
本文主要探讨了粮食安全、土地开发适宜性以及综合生存环境等不同条件约束下的珠江三角洲建设用地最大供给量与供给约束。其结果表明,珠江三角洲地区建设用地开发利用极限为(97.12～110.57)×104hm2,占全区土地总面积的23.30%～26.52%,其中尚未建设利用部分为(21.08～34.53)×104hm2。如果参照1997年～2004年各市年均新增建设用地的话,全区平均尚未建设利用的土地最多只能供给13年使用,其中珠海、佛山和中山只能供给3年～4年,深圳和东莞只能供给7年～8年,广州只能供给约13年;如果再考虑用地区域与供地区域可能不重叠的话,则土地可供时间更短,上述诸市很快将陷入无地可供的境地。惠州、肇庆和江门是珠江三角洲为数不多的3个可建设用地比较充裕的地区,但随着经济发展的不断加快并伴随着建设用地的不断扩大,其土地资源的有限性与经济社会发展之间的矛盾也将逐渐突显。从建设用地开发利用极限看土地供给,珠三角多数城市可供建设的土地资源显得十分匮乏。将来的发展必须从严控制土地供应,科学合理地设置土地供应门槛,提高建设用地效率与质量。 相似文献
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城市空间扩展对区域洪涝孕灾环境的影响 总被引：1，自引：1，他引：0
城市空间增长直接改变地表不透水面、河流景观等洪涝孕灾环境,引起产汇流过程紊乱和涝灾发生。采用多源数据及GIS、实地勘测等多分析手段,基于洪涝孕灾环境特征变化视角,分析当前江宁开发区城市空间快速增长与涝灾频发的影响关系：开发区成立至今城市建设用地增加了10.34倍,水面率下降近50％;目前全区不透水率48．12％,主要建设用地平均不透水率超过70％;研究区城市空间增长直接驱动下用地不透水率及格局、径流路径与江水区分布以及河流景观特征及行洪能力显著改变,最后分析提出产水量大、汇流集中且河流排洪差的主要洪涝孕灾环境敏感区,为用地布局的水文安全及洪涝预防体系建设提供参考。 相似文献
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基于层次分析和移动窗口方法的济南市建设用地适宜性评价 总被引：3，自引：0，他引：3
快速城市化使城市建设用地快速增长,但城市土地资源的有限性要求城市土地必须集约利用和合理开发,以实现城市可持续发展.进行城市建设用地适宜性分析有助于优化城市土地配置.本文以济南市为例,应用SPOT和ALOS高分辨率遥感数据进行土地利用解译与分类,基于ArcGIS、Fragstats软件平台,采用层次分析(AHP)与移动窗口相结合的方法,将景观指标融入建设用地适宜性评价因子中,并结合城市土地利用的自然和其他限制因子,对济南市2004年城市建设用地的适宜性进行了评价和等级划分,最后利用2009年土地利用现状图对评价结果进行有效性和可靠性分析.评价和分析表明,2004年适宜于城市建设用地的区域主要分布在城市中心以及东西部区域,2009年新增加的建设用地分布范围与2004年适宜性评价结果大致吻合,评价结果具有一定准确性和实用性.研究结果可为城市建设用地增长管理提供参考依据和决策支持. 相似文献
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基于SBM-Undesirable和Meta-frontier模型的城市建设用地利用效率研究 总被引：1，自引：0，他引：1
《资源科学》2017,(5)
提高建设用地利用效率是今后及未来一段时期满足城市建设用地需求的关键之举。在考虑非期望性产出(环境污染)的情况下,论文基于中国238个地级市2000-2014年的面板数据,利用SBM-Undesirable和Metafrontier模型,考察了共同前沿、群组前沿下不同类型城市的建设用地利用效率。结果表明:(1)不同类型城市之间的建设用地利用效率存在显著差异,在共同前沿下,2000-2010年效率均值从高到低依次为区域综合型城市、工业主导型城市、其他类型城市、资源型城市;在群组前沿下,效率均值没有呈现明显的城市类型分异特征。(2)比较共同前沿与群组前沿下不同类型城市的建设用地利用效率,其他类型城市与区域综合型城市相差较小,分别为0.082、0.106,其次工业主导型城市,为0.118,排在末位的是资源型城市,达到0.267,共同前沿下的差异与群组前沿下的无分异,恰恰印证了本文从城市类型异质性视角下考察建设用地利用效率的科学性与合理性。(3)在将环境污染作为一种非期望性产出的情况下,建设用地利用效率普遍偏低,特别是资源型城市,效率均值不超过0.6,说明在加强生态文明建设的背景下,城市建设用地利用效率存在很大的改善空间。据此提出:在改善城市土地管理工作时,不能简单"一刀切",应考虑城市类型异质性,制定差别化的城市土地管理方案。 相似文献
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区域建设用地集约利用综合评价——以江苏省为例 总被引：20，自引：2，他引：20
在前人研究的基础上，从土地经济效率和社会效率等方面出发，构建了区域土地集约利用综合评价体系，结合江苏省实际情况，对江苏全省及65个县市区的土地集约利用水平进行综合评价研究，并指出其区域差异和变化趋势，提出提高土地集约利用水平的政策建议。研究结果表明：①江苏省建设用地集约利用水平整体从粗放扩张向集约利用转变；②江苏省虽然整体处于全国和东部地区前列，但与上海等省(市)相比建设用地集约利用水平还有一定的提升空间；③苏南、苏中和苏北地区建设用地集约利用水平差距显著；在经济发展水平相似地区内，不同县市区建设用地集约利用水平的差距也十分明显。文章指出，针对不同类型地区的经济发展规律和用地特征，设计区别性的用地政策，能够从宏观上指导不同类型地区的用地方向，避免低水平重复建设，提高土地利用集约程度，促进社会和谐发展。 相似文献
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土地用途管制的外部性、内部性问题及制度改进探讨 总被引：2，自引：0，他引：2
探讨了由于我国土地用途管制制度不完善而导致的管制外部性与内部性问题,这种外部性与内部性问题导致土地利用中存在几个问题:管制弹性的缺乏与资源市场配置相左,导致土地配置效率受损;管制中的区域外部性造成土地利用收益分配失衡,加剧区域发展不协调;内部性问题的存在使得寻租现象较为严重,并导致建设用地过量供给与农用地(或生态用地)低水平利用的共存。基于此,提出了现行土地用途管制制度应进行制度改进,建立市场增进型土地用途管制制度,并简单探讨了一个制度改进的政策工具——区域间土地利用功能置换。 相似文献
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Marjorie Armstrong-Stassen Margaret Landstrom Ramona Lumpkin 《The Information Society》1998,14(2):153-164
This study examined how students who had no prior experience with videoconferencing would react to the use of videoconferencing as an instructional medium. Students enrolled in seven different courses completed a questionnaire at the beginning of the semester and again at the end of the semester. Students at the origination and remote sites did not differ in their reactions toward videoconferencing but there was a significant difference for gender. Women reacted less favorably to videoconferencing. Compared to the beginning of the semester, students reported significantly less positive attitudes toward taking a course through videoconferencing at the end of the semester. There were no significant differences in students' attitudes toward videoconferencing across courses at the beginning of the semester but there were significant differences across the courses at the end of the semester. The results suggest the need for better preparation for both students and instructors. 相似文献
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A joint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology his co-workers from Norway US Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells suggesting that China's projected climate warming could decrease the pest's numbers. The study was published in Proceedings of the National Academy of Sciences on September .…… 《中国科学院院刊(英文版)》2008,22(1):6-7
Ajoint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology and his co-workers from Norway, US and Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells, suggesting that China＇s projected climate warming could decrease the pest＇s numbers. The study was published in Proceedings of theNational Academy of Sciences on 17 September, 2007. 相似文献
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Caroline Haythornthwaite 《The Information Society》2001,17(3):211-226
A computer-mediated group is a complex entity whose members exchange many types of information via multiple means of communication in pursuit of goals specific to their environment. Over time, they coordinate technical features of media with locally enacted use to achieve a viable working arrangement. To explore this complex interaction, a case study is presented of the social networks of interactions and media use among members of a class of computer-supported distance learners. Results show how group structures associated with project teams dominated who communicated with whom, about what, and via which media over the term, and how media came to occupy their own communication niches: Webboard for diffuse class-wide communication; Internet Relay Chat more to named others but still for general communication across the class; and e-mail primarily for intrateam communication. Face-to-face interaction, occurring only during a short on-campus session, appears to have had a catalytic effect on social and emotional exchanges. Results suggest the need to structure exchanges to balance class-wide sharing of ideas with subgroup interactions that facilitate project completion, and to provide media that support these two modes of interaction. 相似文献
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A research group led by Prof. ZHAI Qiwei from the Institute for Nutritional Sciences under the CAS Shanghai Institutes for Biological Sciences has discovered that even relatively low doses of resveratrol-a chemical found in the skins of red grapes in red wine-can improve the sensitivity of mice to the hormone insulin according to a report in the October issue of Cell Metabolism.…… 《中国科学院院刊(英文版)》2008,22(1):14-15
Aresearch group led by Prof. ZHAI Qiwei from the Institute for Nutritional Sciences under the CAS Shanghai Institutes for Biological Sciences has discovered that even relatively low doses of resveratrol--a chemical found in the skins of red grapes and in red wine--can improve the sensitivity of mice to the hormone insulin, according to a report in the October,2007 issue of Cell Metabolism. As insulin resistance is often characterized as the most critical factor contributing to the development of Type 2 diabetes, the findings“provide a potential new therapeutic approach for preventing or treating” both conditions, the researchers said. 相似文献
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Electronic data interchange (EDI) provides means for interorganizational communication, creates network externalities, requires an advanced information technology (IT) infrastructure, and relies on standards. In the diffusion of such innovations, institutional involvement is imperative. Such institutions contain governmental agencies, national and global standardization organizations, local government, and nonprofit private organizations like industry associations. The last type of organizations we call intermediating institutions. They intermediate or coordinate ("inscribe") the activities of a group of would-be adopters. Unfortunately, little is known of how these organizations shape the EDI diffusion trajectory. In this article we examine one specific type of intermediating organizations?industry associations?and how they advanced the EDI diffusion process in the grocery sectors of Hong Kong, Denmark and Finland. We identify six institutional measures, placed into a matrix formed by the mode of involvement (influence vs. regulation) and the type of diffusion force (supply push vs. demand pull), that can be mobilized to further the EDI diffusion. Industry associations were found to be active users of all these measures to varying degrees. Their role was critical especially in knowledge building, knowledge deployment, and standard setting. Furthermore, institutional involvement varied due to policy and cultural contingencies and power dependencies. 相似文献
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Puay Tang 《The Information Society》1998,14(1):19-31
The increasing prospects of digital piracy has prompted the perceived need by electronic publishers to adopt technical systems of protection, and governments to reform their copyright laws. This article is a preliminary study of the management of intellectual property by electronic publishers, defined as those involved in the production of online databases, and CD-ROMs. It focuses on three main issues: (1) how electronic publishers view the increasing threat of piracy; (2) the methods of protection employed to protect intellectual property in digital format; and (3) the importance of technological protection of intellectual property in electronic publications. The analysis is based on a sample of 23 UK electronic publishers. The interviews revealed an interesting assortment of protection methods and did not show that technological protection was a preferred way. Instead, the means of protection, in addition to copyright law, comprised niche markets, pricing, trust, bad publicity, and nontechnical and technical means. 相似文献
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Milton Mueller 《The Information Society》2001,17(3):151-163
Long-standing conflict between domain name registrants and trademark holders prompted the Internet Corporation for Assigned Names and Numbers (ICANN) to create a global, mandatory arbitration procedure known as the Uniform Dispute Resolution Policy (UDRP). The UDRP has been used in 2166 cases involving 3938 domain names as of 1 November 2000. The policy gives the initiator of a complaint, generally a trademark holder, the right to choose which ICANN-accredited dispute resolution service provider (RSP) will handle the case. During the preparation of the UDRP,some feared that complainant selection would lead to "forum shopping" that might bias the results. This article performs a statistical assessment of the forum-shopping thesis and finds support for it. There are statistically significant differences in the various RSPs' propensity to take away names from defendants; there are also major differences in the number of cases brought to each RSP. RSPs who take away names have the larger share of cases. The study examines other variables that might explain differences in market share, such as price, the plaintiff's nationality, or the time taken to decide a case. It finds that nationality and time also are correlated with market share. The study concludes that shopping for a favorable outcome is an important factor in the UDRP. 相似文献
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Prof. Raymond C.K. Chen a neuropsychologist with the CAS Institute of Psychology has made novel progress in his studies of schizophrenia. His work has been reported by a recent issue of Behavioural Neurology.…… 《中国科学院院刊(英文版)》2008,22(1):15-15
Prof. Raymond C.K. Chen, a neuropsychologist with the CAS Institute of Psychology, has made novel progress in his studies of schizophrenia. His work has been reported by a recent issue of Behavioural Neurology. 相似文献
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Active biological molecules functional structures can be fabricated into a bio-mimetic system by using molecular assembly method. Such materials can be used for the drug delivery disease diagnosis therapy new nanodevice construction.…… 《中国科学院院刊(英文版)》2008,22(1):22-22
Active biological molecules and functional structures can be fabricated into a bio-mimetic system by using molecular assembly method. Such materials can be used for the drug delivery, disease diagnosis and therapy, and new nanodevice construction. 相似文献
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《中国科学院院刊(英文版)》2014,(3)
<正>In Xishuangbanna,one of China’s most biodiverse regions,landscape has changed dramatically during the past three decades due to the conversion of tropical rainforest to rubber plantations.In steep areas,terraces are often constructed before planting rubber trees,which causes two important changes in the soil:the destabilization of soil in the bench terraces and the increased vulnerability of unvegetated riser faces to erosion.Few studies have documented the nature and intensity of erosion on bench terraces.Prof.LIU Wenjie and his colleagues from the Xishuangbanna Tropical Botanical Garden(XTBG)conducted a study in Menglun County(21°5′39″N,101°15′55″E),Xishuangbanna to evaluate the influence 相似文献